Selector action for multiple key devices



5, 1940- e. w.- CARLSON ET m.

V SELECTOR ACTION FOR MULTIPLE KEY DEVICES Filed March 28, 1938 3 sheets sheet 1 mm? mm 8 Nov. 5, 1940.

SELECTOR ACTION FOR MULTIPLE KE Filed Malrch 2a. 1958 G. W. CARLSON ET AL Y DEVICES- 3 Sheets-Sheet 2 INVENTQR George W Carlson flan id Peterson 764. 7 l bat-: 2,

Nov. 5, 1940.

G. w. CARLSON ET AL SELECTOR ACTION FOR MULTIPLE KEY DEVICES Filed March 28 1938 3 Sheets-Sheet 3 INVENTOR G eorge W Carlson David Peterson & m a

Patented Nov. 5, 1940 PATENT OFFICE SELECTOR ACTION DEVICE FOR SMULTIPLE na George w. Carlson and David Peterson, Pittsburgh, Pa.,assignors,

by none alsslgnmentl, to

Robert H. McClintic, Pittsburgh, 1.

Application March 28,

4 Claims.

. This invention relates to a pneumatic action for effecting the operation of multiple key devices, as for example, typewriters, but is applicable to use in any multiple key advice where a plu- 5 rality of elements are adapted to be selectively moved through the control of a record sheet. The invention is especially useful in connection with record controlled systems where the selector merely initiates subsequent operations performed by a more powerful mechanism. For example, in the case of typewriters, the selector merely effects an operation by means of which a given key is selected to be operated by an actuating device.

The invention constitutes an improvement over the selector mechanism disclosed inthe prior application of George W. Carlson, Serial No. 68,068, filed March 10, 1936, for Pneumatic action for typewriters and other multiple key devices. The said prior application discloses a selector action of the general character to which the present invention pertains and illustrates the same as ap plied to a pneumatically operated typewriter. In thesaid application there is disclosed a selector 2 in which there are a plurality of pouches, the pouches being arranged in rows within a casing, the interior of the casing being connected to a suction pump so that a vacuum is-constantly maintained against one surface of the pouches. In back of each pouch there is a chamber which communicates to a record controlled opening in a tracker bar. These individual chambers for each pouch are connected through a restricted bleed opening to the vacuum chamber or vacuum pump. Located in the vacuum chamber adjacent each pouch is a hinged finger. The arrangement is such that when an impulse of atmospheric air is admitted through an opening in a tracker bar, the pouch is flexed by the difierence of pressure toward the side on which a constant vacuum is maintained imparting a movement to the finger which is adjacent the pouch. This finger is connected to a rod which passes through an orifice plate and the motion of the rod is utilized in eil'ecting the selection. When the impulse of air 45 has been cut oil from the tracker bar opening, suction is restored to the chamber to which air has been admitted by the bleed opening but a spring is required to return the finger back to its 50 normal position' This construction, while being generally satisfactory is open to certain objections. The first is that where the rods pass through the orifice plate, there must be a close fit between the rods and the openings through which they pass to minimize the amount of air which can leak in around the rods because the 1938, Serial No. 198,430 (Cl, 19720) leakage or air around the rods serves to destroy the vacuum which must be maintained in the casing. Because of the tight fit of the rods in these openings, there necessarily exists a considerable friction to the reciprocation of the rods 5 and the amount of power being relatively small, this friction slows down the operation of the device. As wear occurs in the wires or rods, leak age develops. Sometimes a rod will stick and the light spring which opposes the action of the 10 finger is insufi'icient to return the rod finger to its normal position. Also, after a continued period of operation, the springs are likely to break, requiring that the entire structure be opened up for repairs.

According to the present invention, there is provided an improved selector mechanism wherein the fingers themselves are at all times open to atmospheric air, and atmospheric air is used to move the fingers in both directions. This elim- 2O inates any requirement for springs whatever and the arrangement also eliminates-any requirement of the selector being located in a vacuiun chamber. The use of an orifice plate is entirely done away with and the cost of the entire assembly is very much reduced. Not only is the cost of the assembly reduced, but a more effective and quicker action is secured and there is no loss of vacuum through leakage of air with the result that the suction developed by the pump is more effectively used. The elimination of springs eliminates one of the principal service difficulties, first because there are no springs to break, and second because the movable parts are at all times accessible without the opening of any casing which normally has to be tight.

The invention may be readily understood by reference to the accompanying drawings which illustrates one embodiment of our invention and in which- Figure 1 is a top plan view of a selector embodying our invention, the cover being for the most part broken away and certain parts being shown in section.

Figure 2, is a side elevation, partly in section, and partly in elevation, two of the automatic pouch units being shown in section with the fingers of one being in the normal position and the fingers of the other moved to the selecting position.

Figure 3 is an elevation showing one of two cooperating panels used in effecting the assembly and on which the secondary pouches are formed.

Figure 4 is a view similar to Figure 3 of the other of the two panels used in eifecting the assembly, this being the panel on which the primary or main pouches are formed.

Figure 5 represents a horizontal section in the of a series of cross units 3 which are held in spaced relation by spacer blocks 5 at each end,

there being openings 5 between the parallel cross members 3. Each cross member has a plurality of pouch units thereon, the pouch units correspending to the number of keys or other devices to be selectively operated. The pouch units in the several rows are staggered so as to be out of alinement to thereby accommodate the several motion transmitting rods or wires 6 which are actuated by the several pouches.

Each cross member 3 is comprised of two panels in face, to face relation, one of these panels being designated 1 and the other being designated a. Each panel 1 has a plurality of cavities or chambers 9 formed therein. Leading from each chamber 9 is a transversely extending passageway l0 communicating with a tube l l, these tubes being fitted into passages H], as shown in Figure 2 to form an airtight connection. Glued to the front of the panel I is a continuous strip of thin leather or other suitable material l2. Where the leather overlies the cavities 9, it forms a flexible pouch i3 as best shown in Figures 1 and 2. Air cannot pass from the chamber 9 back of the pouch through the leather nor can it flow in the reverse direction. Secured to each pouch diaphragm I3 is a light hard disk Hi, the disk being located on the side of the pouch diaphragm which is away from the chamber 9. A continuous strip of leather i2 is used instead of disconnected isolated diaphragms merely because this is a cheap and convenient way of forming a series of air tight diaphragms over the chambers 9. The chambers 9 have no communication with one another, the only passage to outside air being through the passages in and the tubes H.

The other panel member 8 has a continuous channel l5 formed therein extending through the major portion of the length .of the panel, but terminating short of the ends of the panel. A

' plurality of holes l6 are formed in this panel, the

holes l6 corresponding in number to the chambers 9 and being concentric with the chambers 9 when the two panels are pressed in face to face relation. The holes I6 are of smaller diameter than the chambers 9. Secured to the inner face of the channel I6 is a continuous strip of thin leather or other suitable material i1 whichcovers the openings IS. The leather over the openings It forms pouch diaphragms l8 best shown in Figures 1, 2, and 5 which are'of substantially less area than the area of the pouch diaphragms H. A plurality of small holes IQ are formed in the two panels to accommodate screws for securing the panels together. When the panels have been assembled to the point shown in Figures 3 and 4, they are put together in face to face relation and in such manner as to be air tight.

When they are thus put together, there is formed a longitudinally extending air passage between the two panels. This air passage has a reduced extension 2| leading to a cross passage 22 formed in the members i and 8. The arrangement is such that when the panels are assembled and a number of them are in parallel relation as shown in Figure 1, there vn'll be a continuouszpassage or manifold 23 communicating with all of the air spaces in the several cross units. A single tube 24 communicates with this passage 28 and enablesthe passage 23 to be connected to an ex-- hausting or vacuum pump not shown.

Secured to the outside of each panel member 8 are a plurality of hinged fingers 25, these fingers being hinged by means of a leather strip 25 glued to the back of the finger and glued and tacked to the member 8. The number of fingers corresponds to the number of pouches in the cross piece, and each finger passes vertically across the outside of one of the holes l6. Each finger is provided with an inwardly extending projection 21 that bears against its respective pouch i8. A reinforcing disk 28 is located against the inner face of the pouchv l8 and a tack or small screw passing through the member 28, the pouch l8, and into the projection 21 serves to secure or attach the finger to its respective pouch. In-

Figure 9 the projection 21 is illustrated as being carried on part of the leather 26, whereas in Figure 10 the corresponding projection 2'? is illustrated as being carried directly on the finger. Either form of assembly may be conveniently used. Each finger has an upwardly extending tip portion 29 having a transverse hole therein to receive a transversely bent terminal portion 6' on the operating rod or wire 6.

Each one of the passages I0 is connected through the elbow II and a tube 30 toone of a series of openings in a tracker bar 3! over'which readily understood by those familiar with pneumatic devices of this character. The record spools have not been illustrated. The tracker bar 3| is provided with a longitudinally extending channel 33. A very minute bleed opening 33' connects each tracker bar opening with the channel 33. The channel 33 is connected through a tube 34 with the pipe 24 leading to the vacuum pump.

Over the selector casing 2 is a cover member 35, the only function of which is to protect the underlying selector from dust and to provide a guard against injury to the selector in handling. The various rods 6 may be connected to devices to be selectively operated in various ways. Figure 8 illustrates the specific application of the selector to a typewriter showing the complete key hook-up for a single one of the rods 5. The wires or rods 6 attached to. the several selector fingers pass forwardly in a common plane from under the cover 35 through a guide bar 36 that maintains them parallel. In Figure 8 there is shown a connection 38 from one of the wires 6 to a hook member 39 hung from the key bar 42 the path of travel of the downwardly moving rocker bar 40 to thereby depress the key 42.

It will be understood that this hook-up is merely typical of one arrangement, which arrangement is more fully described in the aforementioned application of George W. Carlson, and that the invention is also applicable to other installations as for example, it is adapted for use in connection with typewriters wherein the type bars are operated by a power roller one type of which is sold under the trade mark Electromatic typewriter.

The operation of the selector may now be followed. When a vacuum pump creates a suction in the tube 24, air is withdrawn from the spaces between the two panels 1 and 8. This creates a suction tending to, draw all of the secondary or small diaphragms I8 toward the right as viewed in Figure 2, holding the fingers 25 in their normal position. Also, the tracker bar openings being normally closed by the record against the entrance of atmospheric air, a suction is maintained in the chambers 9 behind the larger diaphragms It, the air being withdrawn from the chambers 9 through tubes 30 through the bleed openings 33 in the tracker bar to the chamber 33 and from the chamber 33 through the tube 34 to the exhaust line 24. When a tracker bar opening is uncovered by the record 32, an impulse of air is momentarily admitted through one of the tubes 30, this impulse of air flowing through the tube 30 and the passage I0 into the chambers. Since there is a vacuum on one side of the diaphragm I3 while an impulse of air is admitted to the other side, the diaphragm l3 will be forced to the left asviewed in Figures 1 and 2. The disk H on the diaphragm I4 will strike the disk 28 on the diaphragm [8. Since the area of the diaphragm I3 is considerably. greater than the area of the diaphragm IS, the diaphragm l3 will force the diaphragm l8 toward the left as viewed in Figure 2 rocking the finger 25 a slight distance as shown in the extreme lefthand unit in Figure 2. When the tracker bar opening has been closed, shutting off the impulse of air to the chamber 9, the atmospheric air which has been admitted will be drawn to the suction pump through bleed opening 33 and a vacuum will be restored in the chamber 9. The diaphragm [8, then being exposed on the left face to atmospheric air and to a vacuum on the righthand face, will be flexed in the opposite direction to restore the finger to its normal position. Thus it will be seen that the movement of the finger for each pouch unit from the normal to the selecting position is eifected by the large or primary diaphragm I3 and that the return movement of the finger is eifectcd by the secondary or effectually smaller diaphragm l8. This operation is made possible by the differential areas of the diaphragms i3 and I8.

The operation of the fingers can be eifected much more quickly than where springs are used for moving the fingers in one direction, and the construction is much easier to keep in repair by reason of the fact that the casing as a whole does not have to be kept under a vacuum because no springs are employed and because rods 6 do not have to have any tight working fit in an orifice plate as in the construction shown in the said Carlson application.

While we have shown certain specific embodiments of our invention, it will be understood that this is merely by way of illustration and that various changes may be made in the particular construction and arrangement of parts within the contemplation of our invention and within the scope' of the following claims.

We claim:

1. A pneumatic mechanism oi the class described comprising a pair of spaced opposed diaphragm pouches of different eifective areas, the smaller of the diaphragm pouches during operation being exposed continuously on one side to atmospheric pressure and having its other side exposed to a sub-atmospheric pressure whereby said diaphragm is constantly biased in one direction, the larger of the pouches having one side during operation exposed continuously to sub-atmospheric pressure, there being an enclosed chamber in back of the other side of the larger pouch, record controlled means for selec-' tively admitting air to the chamber, a bleed passage through which air so admitted to the chamber may be withdrawn, and means operated by the movementof the pouches, said last named means being positioned in the atmosphere to one side of both pouches and being attached to the smaller of said pouches, the larger diaphragm transmitting motion to said last named means only by contact with the smaller of the diaphragms and being free to move relatively to the smaller one.

2. A pneumatic mechanism comprising a supporting body having a chamber 'formed therein with a flexible diaphragm over the chamber, an air passage leading to the chamber, a tracker bar having an opening to which said chamber communicates through said air passage, a second diaphragm in the body effectively smaller than thefirst, an intermediate chamber in the body between the two diaphragms having a passageway for connection to a suction pump, there being a bleed opening between the first chamber and the intermediate chamber, the face of the second diaphragm which is away from the intermediate chamber being exposed to atmosphere whereby it is normally biased inwardly toward the first diaphragm, and an element outside the supporting body connected to the second diaphragm only for movement therewith, the larger diaphragm transmitting movement to said element in one direction only through the second diaphragm, the larger diaphragm being free to move in one direction independently of said element.

3. A pneumatic mechanism of the class described comprising a plurality of reciprocable rods, a hinged finger attached to each rod, a pneumatic unit for moving each finger comprising opposed primary and secondary diaphragms, the primary diaphragm being larger than the secondary and being positioned to transmit motion to the secondary diaphragm by contact therewith, each secondary diaphragm being connected with its respective finger, a suction chamberbetween the two diaphragms of each unit, there being a second chamber at the opposite side of the primary diaphragm of each unit, the two chambers communicating through a bleed opening, and pneumatic circuits including a suction line leading from said suction chamber and tracker bar controlled passages leading to the second chambers of the several units and by means of which the primary diaphragms may be selectively flexed to move the fingers in one direction and whereby a pneumatic biasing pressure is constantly maintained on the secondary diaphragms to yieldably resist such flexing movement of the primary diaphragms and return such primary diaphragms to their initial position after they have been operated, all of said fingers being located outside of the pneumatic channels through which their operation is efiected and having their connections with the secondary diaphragms exposed to amosphere.

4. A selector unit for multiple key devices comprising a plurality of spaced members each having a suction channel therein, a plurality of hinged fingers in the spaces between said members, all of the fingers being of the same efiective length and projecting beyond the plane of one face of the unit, the row of fingers in each space being out of alignment with the fingers in the other spaces, each finger having a connecting rod attached to the projecting end thereof, each of said members having a row of selectively controlled pneumatic pouches contained therein, there being one pouch for each finger, each of said members having a row of like diaphragms therein, one in front of each pouch, the exterior of each diaphragm being exposed to air, the interior being open to the suction channel in the member on which it is carried, said fingers being attached to their respective diaphragms, said pouches being normally spaced from their respective diaphragms, each pouch being arranged upon operation thereof to press its respective diaphragm outwardly, all of the diaphragms and pouches being in the same plane intermediate the ends of the fingers 'wherebyall fingers are moved to substantially the same extent by-the operation of the pouches.

GEORGE W. CARLSON. DAVE PON. 

